Metallic workpieces, such as surgical needles, are frequently subjected to various operations, such as grinding, polishing, bending and drilling. These operations, whether performed manually or in an automated manner, will normally deposit debris, such as filings, ground metal or particles of grinding material, on the workpiece. In addition, grease or other dirt either from the hands of the operator or, for example, from lubricants applied to the machinery on which the piece is worked, may also be deposited on the workpiece. Accordingly, it is normally necessary to clean the workpiece after it has undergone one or more processing steps.
Freon is one solvent which has been used to clean metallic workpieces. Recently, however, environmental concerns in connection with Freon and other fluorocarbons has led to the use of aqueous solvents for cleaning metallic workpieces. Extended contact of a metallic workpiece with an aqueous environment, however, may result in oxidation of the metal, causing roughness, loss of lustre or pitting of the workpiece. This is particularly true where the workpiece has sharpened edges, polished surfaces or a sharp point as is the case with a surgical needle.
It is therefore an object of the present invention to provide methods for drying metallic workpieces which have been washed with an aqueous solvent.